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| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 5 |
| 2 | 12 |
| 3 | 30 |
| 4 | 70 |
| 5 | 166 |
| 6 | 382 |
| 7 | 881 |
| 8 | 2002 |
| 9 | 4540 |
| 10 | 10210 |
| 11 | 22891 |
| 12 | 51050 |
| 13 | 113506 |
| 14 | 251430 |
| 15 | 555466 |
| 16 | 1223680 |
| 17 | 2689591 |
| 18 | 5898290 |
| 19 | 12909880 |
| 20 | 28204178 |
| 21 | 61515521 |
| 22 | 133961048 |
| 23 | 291308806 |
| 24 | 632628710 |
| 25 | 1372170030 |
| 26 | 2972790738 |
| 27 | 6433570445 |
| 28 | 13909116418 |
| 29 | 30042364980 |
| 30 | 64830556978 |
[2,5,12,30,70,166,382,881,2002,4540,10210,22891, 51050,113506,251430,555466,1223680,2689591, 5898290,12909880,28204178,61515521,133961048, 291308806,632628710,1372170030,2972790738, 6433570445,13909116418,30042364980,64830556978] |